The present invention relates to a tire attitude control device and tire attitude control method for controlling the attitude of a rolling tire mounted on a vehicle.
A tire mounted on a vehicle and subjected to a load is affected by the suspension mechanism of the vehicle, resulting in a camber angle that is not equivalent to zero when the tire is in a stationary state. The same holds true in a rolling state. Further, the geometry of the suspension mechanism changes according to the change in load, and this change varies the attitude (camber angle) of the tire. In general, toe-out, where the wheel extends outside the direction of vehicle travel, and a negative camber, where the wheel tilts toward the inside of the vehicle with respect to the direction perpendicular to the contact area of the wheel, tend to occur when a high load is applied.
Thus, since the attitude of a tire changes when mounted on a vehicle, the shape of the tire contact area that contacts the road deviates from a symmetrical shape. Accordingly, the force produced within the tire contact area also exhibits asymmetrical distribution, which causes uneven tire wear.
On the other hand, JP 2005-343281 A describes a method and device for estimating the dynamic state of a tire, and a tire with a sensor.
JP 2005-343281 A describes a method whereby strain gauges are installed on a tire in two locations symmetrical in the width direction using the center position of the tire tread as a reference, ground contact lengths are found from the output waveforms of the strain gauges, and the load, lateral force, and longitudinal force are estimated from the identified ground contact lengths.
However, while this device of prior art estimates items such as the load and longitudinal force applied to the tire, it does not control the attitude of the tire. Accordingly, the device is not capable of suppressing uneven tire wear.